Kiymaz, DenizKiymaz, AykutTekoglu, SerpilMayr, FelixDincalp, HalukZafer, Ceylan2023-01-122023-01-1220220040-60901879-27310040-60901879-2731https://doi.org/10.1016/j.tsf.2022.139535https://hdl.handle.net/11454/76910In a supercapacitor, determining the cells' internal dynamics and limiting factors on the efficiency is essential for device designs. In this context, electrochemical impedance spectroscopy is a powerful tool in investigating device kinetics. This study explained the performance improvement in nanostructured MnO2 electrodes from a diffusion perspective. Firstly, we reported morphological features of flower-like nanosheet MnO2 and nanowire MnO2 with identical crystal structure (alpha-MnO2 phase) and capacitance-voltage properties. Then, the factors limiting the bias voltage-dependent capacitance efficiency were explained via electrochemical impedance spectroscopy by setting up a three-electrode system. Both resistance and capacitance vs. frequency plots provided important information on ion diffusion and charge transfer mechanisms.en10.1016/j.tsf.2022.139535info:eu-repo/semantics/closedAccessManganese dioxideHollanditeNanostructureNanosheetSupercapacitorElectrochemical impedance spectroscopyChemical solution depositionImpedanceMno2ElectrolytesStateSpectroscopyPerformanceNanosheetsRedoxArticle762WOS:0008857825000012-s2.0-85140139139Q2Q3